Submission #17445

#	Time	Username	Problem	Language	Result	Execution time	Memory
17445		atomzeno	지우개 (GA4_eraser)	C++98	100 / 100	18 ms	1864 KiB

eraser

#include<cstdio>
#define MOD 1000000007
long long a[100001];
long long x,y,z,answer;
int main(){
    int i,j,n;
    scanf("%d",&n);
    for(i=0; i<n; i++){
        scanf("%d",&j);
        a[j]+=j;
        a[j]%=MOD;
    }
    for(i=1; i<=100000; i++){
        x+=a[i];
        x%=MOD;
        y+=a[i]*a[i]%MOD;
        y%=MOD;
        z+=a[i]*a[i]%MOD*a[i]%MOD;
        z%=MOD;
    }
    answer=x*x%MOD*x%MOD;
    answer-=3*x%MOD*y%MOD;
    answer+=MOD;
    answer%=MOD;
    answer+=2*z%MOD;
    answer%=MOD;
    answer*=166666668;
    answer%=MOD;
    printf("%lld",answer);
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 16 / 16
• Subtask 4: 17 / 17
• Subtask 5: 26 / 26
• Subtask 6: 28 / 28